There are stereoscopic image display devices that realize a stereoscopic view for an image observer observing two (or more) images (hereinafter, these may be referred to as “parallax images”) having parallax. The system of the stereoscopic image display devices is largely divided into a glasses system in which parallax images are divided and input to the left and right eyes by using glasses and a naked eye system in which parallax images are input to the left and right eyes through a special optical component without using glasses.
As the stereoscopic image display devices of the naked eye system, there are stereoscopic image display devices of various types such as a parallax barrier type using a parallax barrier as the special optical component that enables stereoscopic recognition of parallax images, a lenticular lens type using a lenticular lens as the special optical component, and the like.
By using the stereoscopic image display device that realizes a stereoscopic view, in other words, displays a stereoscopic image (three-dimensional (3D) image), it is preferable that an ordinary planar image (two-dimensional (2D) image) can be also displayed without any problem. In other words, a configuration is preferable in which switching between the display of a stereoscopic image and the display of a planar image can be performed.
As a stereoscopic image display device that can switch between the display of a stereoscopic image and the display of a planar image, a mobile information terminal is generally used in which two display optical systems are arranged, and both text information and image information can be displayed so as to be easily recognized by switching between the two display optical systems (for example, see JP-A-2007-187823).